html, body {
  background: #111;
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

#ui-container {
  display: flex;
  flex-direction: row;
  height: 100%;
}

#ui-sidebar {
  width: 264px;
  height: 100%;
  background: #3D4145;
}

#ui-content {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
}

#main{ 
  flex-grow: 1; 
  height: 100%;
}

canvas {
  display: inline-block;
}